Wood has long been used as a material for a variety of articles, e.g., decking, furniture, structural framing and sheathing, etc. A natural product, wood tends to degrade when exposed to the environment, e.g., dampening or even soaking with water, etc. Such degradation can impair the aesthetic appearance of a wood article or construction or even degrade the structure integrity thereof, sometimes necessitating expensive maintenance, repairs, and replacement.
Accordingly it has been known to apply surface treatments, e.g., stains and paints, to wood articles to slow the degradation thereof. Current coating technologies can extend the life of the wood but require frequent maintenance and typically alter the appearance of the wood. A number of polyurethane and lacquer products are commercially available for this purpose. U.S. Pat. No. 4,539,047 (Crockatt et al.) discloses one example of a surface coating to protect wood.
It has also been known to impregnate wood, e.g., to penetrate it such as by pressure treating with preservative materials, e.g., so-called CCA or chromated copper arsenic formulations.
Some examples of materials and processes used to treat wood are disclosed in U.S. Pat. No. 4,325,993 (Schroder), disclosing use of solutions containing copper, chromium, and/or arsenic solutions; U.S. Pat. No. 5,783,258 (Garapick), disclosing use of white mineral oil and optional fungicide; U.S. Pat. No. 6,045,865 (Felby et al.), disclosing use of oxidase enzyme, impregnating substance, and oxidizing agents; U.S. Pat. No. 6,248,402 (Guyonnet et al.), disclosing a process comprising vacuum treatment, thermal treatment, impregnation, and polymerization; U.S. Pat. No. 6,250,350 (Muraki et al.), disclosing a pressure impregnation process; U.S. Pat. No. 6,428,902 (Amundson et al.), disclosing use of wax surfactant-water emulsions; U.S. Pat. No. 6,652,986 (Peldszus et al.), disclosing use of preservative agents based on metal compounds and impregnation with aqueous solution of salt of trimercapto-s-triazin, dithiocarbamate, or trithiocarbonate; U.S. Pat. No. 6,753,016 (Ghosh), disclosing use of compositions containing iron salts and oxidants and optional microbiocidal agents; U.S. Pat. No. 6,953,501 (Kelley et al.), disclosing use of a mixture of creosote and a polymer; and U.S. Pat. No. 7,001,452 (Zhang et al.), disclosing use of poly-aspartic acid free compositions of metal compounds, complexing agents, and vinyl-based polymers.
In recent years, concern has been raised about potential safety risks and environmental effects presented by some wood treatment approaches, leading to development of variations, e.g., alkaline copper quat- and copper azole-containing formulations and borate-based formulations.
Current pressure treated wood degrades too quickly for many long-term uses. This requires replacement of the finished product after an undesirably limited period of time. In addition, special finishes, fasteners, etc. may have to be used when using pressure treated wood in order to be compatible with the treatment material.
Plastic or fiberglass products may be made to appear similar to wood but are often deemed to be aesthetically lacking on some fashion as not being “real wood”.